In the prior art, various connection devices have been disclosed including those in the following U.S. Patents:
U.S. Pat. No. 3,031,217 to G. A. Tinnerman, 4-24-62, disclosed an angle clip with arched protrusions on an outer face; PA1 U.S. Pat. No. 3,343,811 to E. J. Kusel et al, 9-26-67, disclosed a curved pushdown end on an angle clip; the downward leg was narrow and slotted; PA1 U.S. Pat. No. 3,529,808 to E. A. Siebers, 9-22-70, disclosed an angle clip with a corrugated arm for frictional retention within a "U" shaped railing; the downward leg was narrower, the clip could be forced along the railing to intermediate locations, and the downward leg was slotted; PA1 U.S. Pat. No. 3,942,763 to A. Helterbrand and A. H. Logan, 5-9-76, disclosed a clip with a pulldown provision; the downward leg was narrow and slotted; the railing sides were narrowed at the bottom rather than returned.